The Aetheric Dynamo from steampunk sculptor Dan Cohen is a notional ghost-catching apparatus of great loveliness:
The primary purpose of this machine is the attraction and capture of a lower Aetheric Shell, otherwise known colloquially as a ‘ghost’ or ‘spirit. The secondary function is the transformation of the Shell into remote aetheric antennae, and the transduction of aetheromagnetic energy into electromagnetic current.
(Thanks, Dan!)